Samarkand, Bukhara, Urgench, Balkh, Merv, Nishapur, Herat, Ghazni: One after another the cities of Central Asia toppled before the horsemen bursting from the steppe of Mongolia. Rarely had the world witnessed such a whirlwind of destruction.

Nor had an empire existed so vast as Genghis’s sons and grandsons would establish—to be exceeded, in fact, only by the British Empire of the 19th century. In 1280 Mongol rule stretched from the Yellow Sea to the Mediterranean. Almost as quickly as the empire rose, however, it began to fracture into independent fiefdoms, such as the Golden Horde in Russia, a remnant of which hung on until 1502.

Off and on for more than three decades, first as a Peace Corps program officer, then as a journalist, I have traveled the Mongol realm. Afghanistan, which was part of it, was the first country that I fell in love with. Ukraine was another. And Russia.

Last year I went back to Asia, and also to eastern Europe, to take another look at what remains from that cataclysmic era. I found that a good deal survives. The cathedral at Vladimir in Russia, for example, where the family of Prince Yuri died when the Mongols lit fires to drive them from the loft. And the fortress-like abbey in Hungary where monks, in all probability, hurled missiles upon their besiegers. And in Bukhara I glimpsed domes that, though dating from the 15th century, cannot be much different from those Genghis saw in the 13th.

In Afghanistan even after 750 years people spoke of the Mongol rampage in voices tinged with apoplexy, as if it had happened yesterday. “Only nine!” exclaimed an old man in the once elegant city of Herat.

"That is all that survived here—nine people!" I almost expected to see corpses in the streets.